Method of making hinges



NOV. 25, 1952 M GUTHRlE 2,618,838

METHOD OF MAKING HINGEIS Filed Oct. 21, 1949 3 Sheets-Sheet l' /M g5 I Patented Nov. 25, 1952 UNITED STATES PATENT OFFICE METHOD OF MAKING HINGES Bernard M. Guthrie, Kokomo, Ind., assignor, by mesne assignments, to Steel Parts Corporation, Tipton, Ind., a corporation of Indiana Application October 21, 1949, Serial No. 122,782

2 Claims. 1

The present invention relates to a metal working process and more particularly to a method of making a butt hinge having integrally formed pintle bosses.

In the manufacutre of heavy duty butt hinges, as for automobile doors, the conventional process includes the rough blanking of the hinge leaves and pintle bosses from a preformed cold drawn steel pintle having parallel, shaped edge portions defining the finished pintle boss crosssection. Since the male boss of one leaf must be interleaved with the female boss of an associated leaf to form a complete hinge, the rough leaf blanks are milled or broached to remove the edge portions of the male boss and the central portion of the female boss and to finish the blank to its final form. It will be seen that at least one-half of the shaped edge portions of the rough blank must be thus removed, resulting in a large metal loss. In addition to the actual metal loss on broaching to shape, the initial rolled bar is expensive due to the necessity of providing parallel edge portions which must be accurately dimensioned to the specifications of the pintle bosses of the finished hinge.

The present invention now provides an improved method of making such hinges by the employment of a simple forging operation performed directly upon a rough blanked hinge leaf. The present invention contemplates the blanking of the leaves, both male and female, in interleaved relation from a hot rolled steel plate or bar having a single central enlarged portion or embossment coextensive with the length of the bar and positioned centrally thereof. The rough blanking of the hinge leaves from the plate or bar is carried out so that the metal previously accumulated at the embossment is employed to form both the male and female pintle bosses of the finished hinge. However, the contour and cross-sectional shape of the embossment and of the rough leaf is not that of the finished pintle boss, so that the embossment preferably is deformed subsequently by means of a forging, a combined forging and finishing, or a forging and subsequent finishing operation to the desired finished contour and cross-sectional shape. At the same time, the leaf shoulders adjacent the pintle bosses are formed to shape by the forging and the accurately forged leaves may later be finished as desired, as by grinding the leaf edges, drilling the pintlc apertures, and the screw or bolt recesses in the leaves.

The advantages residing in the present invention include the employment of substantially all of the metal of the intial rolled bar, the forma- 2 tion of the rough cut blank to a desired configuration by the performance of a simple forging operation, and employment of an initial bar of less complex and cheaper construction.

It is, therefore, an important object of the present invention to provide an improved, simplified, inexpensive method of making butt hinges and similar articles.

Another object of the present invention is the provision of a method of making butt hinges by the forging of leaf blanks having enlarged terminal portions to a finished leaf having pintle bosses of desired contour.

It is a further important object of the present invention to provide an improved method of making hinges by the formation of rough blank-s having terminal portions providing an accumulated mass of metal and forging said accumulated mass to a. desired contour and shape to form a terminal pintle boss.

Still another object of the present invention is the provision of a method of making hinges by the interleaved rough blanking of hinge leaves from a metal bar having a single central accumulated portion, forging the accumulated portion of each leaf to a desired contour, and coining the accumulated portion to form a hinge leaf having a terminal pintle boss.

It is also an important object of this invention to provide a method of making hinges or similar articles embodying complemental thickened parts at adjacent ends thereof comprising cutting the blanks from which said articles are formed along an offset line defining said complemental parts and having portions both traversing and parallel to a thickened medial portion of a stock bar from which said blanks are out.

Other and further important objects of this invention will be apparent from the disclosures in the specification and the accompanying drawings.

On the drawings:

Figure 1 is a bottom plan view of a finished hinge made in accordance with the method of the present invention;

Figure 2 is a side elevational view of the hinge of Fig. 1;

Figure 3 is a plan view of a metal bar from which hinge leaves are blanked as indicated in dotted outline;

Figure 4 is an exploded plan view of male and female rough blanked leaves;

Figure 5 is an exploded sectional view taken on the plane V-V of Fig. 4;

Figure 6 is a side elevational view, with parts broken away and in section of a pair of forming dies used in forging the rough blanked leaves of Figs. 4 and 5, the dies being illustrated in open position;

Figure '7 is a front elevational view, with parts broken away and in section of the dies of Fig. 6 in partially closed position;

Figure 8 is a side elevational view, with parts broken away and in section of the dies of Fig. 6 in closed position;

Figure 9 is a front elevational View, with parts broken away and in section of the dies in closed position; and

Figure 10 is a greatly enlarged fragmentary side elevational view of the pintle boss of the finished hinge of Figs. 1 and 2 with the rough blanked boss superimposed thereon in dotted outline.

As shown on the drawings:

In Figure 1, reference numeral It refers generally to a butt hinge including a pair of leaves H and I2 adapted for pivoting movement about a pintle pin l3.

The leaf N is provided, with a terminal enlarged portion cut away as at M to provide a pair of spaced pintle bosses l5, and the leaf i2 is 2 provided with a central pintle boss I6 adapted to be inserted between the spaced bosses l and IS. The leaf is thus provided with a female pintle portion, while the leaf I2 is provided with a central male pintle portion. The cut away portion M of the leaf defines a sloping shoulder (Figure 2) while a corresponding shoulder it lies on each side of the male boss l6. Each of the pintle bosses is longitudinally apertured to receive a pin I3, and the cut away portion defining the shoulders I! and H3 provide clearance between the bosses upon rotation of the leaves about the pintle pin. Each of the leaves is provided with countersunk apertures L9 to permit securing of the hinge in operative position, as to the body and associated door of an automobile.

In Figure 3, the rough blanking of th hinge leaves I and |2 from steel bar stock is illustrated by means of dotted lines showing the lines of out. It will be seen from this figure that both the male and female leaves are out in interleaved relation from a single bar provided with a central upstanding embossment which defines the rough outline of both the male and female pintle bosses as shown in Figures 4 and 5. The embossment which is designated in Fig. 3 by the reference character A may be conveniently formed in the production of the bar by hot rolling.

It will be seen that the rough out pintle bosses 2| of the leaves H and I2 respectively are identical in cross-sectional contour and that the leaves as out are provided with rough shoulders 22 adjacent each embossment 2|. It will also be observed that the rough cut bosses 2| are not at all similar in cross-sectional configuration or dimension to the bosses of the leaves II and I2 as illustrated in Figures 1 and 2. The blanking operation results in the formation of a sharp lower terminal edge 23 on each of the embossments 2|, and the rough shoulders 22 are inclined in an opposite direction and at a much steeper angle than the finished shoulders I and I8.

In the next step of the method, a rough blanked leaf is bottomed'on a fixed backing die 26 (Figures 6 and '7) provided with a central supporting portion 21 having a plane upper supporting surface 28 receiving a leaf l2, and an arcuately contoured shoulder 29 extending upwardly from the surfac 28 to terminate in a plane upper surface 1 39. The backing die 26 is also provided with side blocks 3| spaced from the vertical edges 32 of the central block 21, and provided with inner inclined camming surfaces 33.

An upper relatively movable forming die 35 is provided for cooperation with the backing die 26, the forming die 35 including a central fixed block 36 carried by a movable support 3'! and having spaced lower plane surfaces 31 and 3B opposing the surfaces 28 and 30 of the backing die 2'! and a contoured recess 39 for cooperation with the contoured shoulder 29 of the backing die 26.

The movable die 35 is provided with springurged side plates 46 having upper, transversely arced, terminal edges 4| received by complementary recesses in the support member 3'! and opposing terminal edges d2 insertable between the side surfaces 32 of the central block 27, and the adjacent camming surfaces 33 of the side blocks 3|. The outer side surfaces of the block 40 are inclined, as at 43, adjacent the terminal edges 42 for cooperation with the camming surfaces 33.

The blocks 46 are secured to the central block 39, as best shown in Figure 9, by means of bolts l having threaded ends retained by threaded recesses 4-5 formed interiorly of the block 36. The shanks of bolts 54 extend through apertures 46 in the blocks 43 registering with the threaded recesses 45, with the enlarged bolt head 41 of each bolt 34 lying outside the block 49 in spaced relation to a countersunk recess 48 formed in the block 43 and communicating with the apertures :36. A relatively heavy compression spring 39 is confined between each bolt head 4? and the associated countersunk recess 46 to resiliently urge each of the blocks it! toward the central block 36.

It will also be noted from Figure 6 that each of the side blocks 49 is provided with an upwardly and rearwardly inclined rear edge 59. The cooperating surfaces 23 and 39 extend across the width of the respective middle blocks 2'! and 36 and cooperate to define the contour and dimensions of the finished pintle boss. The rearwardly inclined edges 55 cooperate with the recesses 23 and 35' to define the sloping shoulders l8 adjacent to and on either side of the central finished pintle boss ll; of the leaf |2.

The entire forming of the finished pintle boss i6 is carried out within the cooperating forming dies 23 and 35 hereinbefore described. It is understood that the forming die 37 is moved downwardly toward the backing die 26 under pressure, as in a suitable press or forging device, and that the embossed portion 2| of the leaf |2 is deformed under this pressure to the contour of the cooperating die surfaces 29 and 39.

As shown in Figure 7, the spring urged side plates or blocks 66 will be forced outwardly from the central block 33 by the pressure of the metal of the boss 2| when the same is subjected to the pressures generated upon movement of the forming dies. The metal will be forced outwardly between the cooperating recesses 29 and 39, and this metal will urge the blocks 46 outwardly against the spring 49 into engagement with the camming surfaces 33 of the side blocks 3| of the backing die 26 However, upon further movement of the dies 25 and 35 toward one another, the camming surfaces 33 force the blocks 49 inwardly toward the block 36 against the pressure of the metal 2| to confine the metal entirely within the cooperating recesses 29 and 39, thus insuring the forging of the metal of the boss 2| to the desired shape. In addition, under the pressures developed during movement of the dies, the edges 50 will form the shoulders l8 adjacent and laterally outwardly of the pintle boss l6 as shown in Figures 2 and 10.

The inward movement of the spring loaded camming blocks 40 effectively coin the side surfaces of the pintle boss to the desired smoothness, thus making unnecessary any finishing of the pintle side surfaces. This treatment of the side surfaces is in effect a coining operation, insofar as manner of treatment and results are concerned, even though it may be carried out as an incident to the main forging operation.

If th contour and cross-sectional dimensions of the finished pintle boss I6 are compared to those characteristics of the rough boss 2| in Figure 10 of the drawings, it will be seen that the contour has been radically changed, that the sharp edge 23 has been eliminated and that the shoulders 22 of the rough cut boss 2| have been transformed into the inclined shoulders l8 of the finished pintle boss.

Although the method has been illustrated in Figures 6-9, inclusive, with particular reference to the forging and coining of a male leaf l2, it will be understood that the female leaf H may be similarly forged by adapting the forming dies 21 and 36 to forge the bifurcated female pintle boss and to coin the interior surfaces thereof.

It will thus be seen that the present invention provides a method for the manufacture of hinges including the accumulation in a pre-rolled section of metal to be later employed in the formation of a pintle boss and the rough blanking of complete leaf hinges from the pre-rolled strip or bar section. The blanking operation is performed to rough shape the male and female pintle bosses from a single accumulated metal section, as contrasted with the prior art. The rough cut or blanked pintle leaves are next forged to final shape, with any fracture line losses during rough blanking being compensated for by the forging operation. The method preferably includes the coining operation carried out as a portion of the forging operation by means of suitably actuated side blocks as hereinbefore described. The coining operation removes any irregularities from the mating edge portions of the pintle bosses and serves to accurately finish the bosses to the desired dimensions.

At the end of the forging stroke, the metal is totally confined by the forming die and the cam loaded sides complete their coining function during this final phase of the operation. In case excessive metal has been accumulated in the prerolled section, this metal may be taken care of by flash between the cooperating die surfaces or by die overflow channels vented to the sides of the hinges where dimensions ar relatively unimportant.

The method of the present invention is particularly adapted for use in the manufacture of hinges and similar articles in which the accumulated metal mass is necessarily so large with relation to the thickness of the material that it cannot be accumulated by a cold forging operation. The method of the present invention results in a saving of 23% by weight of metal over those methods previously employed, in which the initial bar section is provided with spaced parallel terminal metal accumulations and in which the metal of the pintle bosses is removed by a broaching or milling peration.

It will be understood that modifications and variations may be effected without departing from the scope of the novel concepts of the present invention.

I claim as my invention:

1. In a method of making a hinge from a rough blank having a terminal boss projecting from a body portion and a substantially vertical shoulder defined by an edge of said body portion adjacent said boss, the improvements of deforming and finishing said boss and said shoulder to a final configuration by simultaneously forging said boss between closable cooperating dies to increase the protuberance thereof beyond said body portion by metal flow of the boss between the dies and forging said shoulder between the sam dies to incline the same forwardly and downwardly with respect to said boss, and coining the edges of said boss by exerting a force thereon in a plane normal to the plane of closing movement of said dies.

2. In the method of making either of a pair of mating leaf hinges, the steps which comprise forming a metal blank having a planar leaf ortion, a raised accumulation of metal at one end thereof roughly of the volume but differing from the shape of the finished pintle boss and an end surface lying in a plane inwardly of said accumulation and perpendicular to the plane of said leaf portion, and, in a single operation and solely through effecting metal fiow, forging said accumulation into the shap of the finished pintle boss and altering said end surface to slope the same away from the perpendicular to better accommodate movement of the pintle boss on the mating leaf hinge.

BERNARD M. GUTI-IRIE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,602,422 Way et al Oct. 12, 1926 FOREIGN PATENTS Number Country Date 7,109 Great Britain June 7, 1836 

